Current known practice uses a block and tackle, a spring, or a motor, to counter act gravitational forces on a mass, such as a laser lens. All of these solutions have shortcomings. A block and tackle configuration adds considerable mass to the system. If the assembly needs to be moved at high rates of speed and acceleration, additional mass is not desirable due to heat generation and degraded dynamic capabilities. Springs add a negligible amount of mass. However, springs tend to lower the natural frequency of the system dynamics, which at times can cause problems in operating the device in a dynamic environment, especially if the oscillating frequency is close to the natural frequency of the system. The solution to this frequency matching problem is to provide a stiffer spring or a softer spring. The short coming of this solution is that it can cause the drive motor to either push harder against the spring, or act to hold a part of the mass against the gravity field thus heating up the drive motor. The short coming of using a motor for holding up the mass is that the motor begins to heat up due to the continuous current needed to create the force or torque. The additional heat generation causes problems with structures and devices sensitive to heat. It would be desirable to counterbalance a mass in a gravity field without adding a significant amount of mass to the assembly, without generating excessive heat due to continuous current, and/or without lowering the natural frequency of the assembly.